Field emission, structure, cathodoluminescence and formation studies of carbon and Si–C–N nanotubes

Abstract

Catalyst growth carbon and Si–C–N nanotubes have been synthesized successfully by microwave plasma chemical vapor deposition (MPCVD) method using CH4+H2 or CH4+N2 as gas sources, Si columns as additional Si solid sources, and Fe, Fe–Y, Co–Ni as catalysts. Nanotubes consisting of Si, C and N were made under process gases of CH4+N2, and with or without additional Si columns. Well-aligned and nested nanotubes were observed dependent on the catalyst materials. Besides, Si–C–N nanotubes were observed as bamboo-like structure. The as-grown nanotubes were purified in an air furnace to investigate their CL signal shift for potential application involving blue light emission. The field emission results indicate that the emission current densities can be above 10 mA/cm2 at 10 V/μm, and aligned nanotubes belong to better current stability at a constant electric field than nested nanotubes. Nanotubes with a low ID/IG ratio (=0.23) via Raman analysis are achieved. The mechanisms of formation for carbon nanotubes and Si–C–N nanotubes are also discussed.